Some embodiments described herein relate generally to methods and apparatus for a data center network. In particular, but not by way of limitation, some embodiments described herein relate to methods and apparatus for a flattened data center network employing wavelength-agnostic endpoints using wavelength tunable optical transceivers.
Presently, data centers now typically involve a collection of scale-out servers that work collectively to solve large-scale problems. This type of computing often involves extensive data exchange within the data centers, which causes a large amount of traffic to move in an east-west direction (e.g., within the same hierarchal level) within the data centers. For example, in data centers that allow dynamic migration of virtual machines, system images are transferred between original servers and new servers whenever a migration is performed. Thus, this migration of virtual machines generates substantial amount of additional data exchange. For another example, logical and/or physical centralization of storage resources, consolidation of local area network (LAN) and storage area network (SAN) networks, and increases of input/output (I/O) rates per server also contribute to significant increases in east-west traffic rates. To support such applications, it is desirable for datacenter networks to provide high bandwidth and low latency with low complexity and power consumption.
Current data centers are typically built with a multi-tier architecture. Servers in a rack are connected to one or two top-of-rack (ToR) switches. These ToR switches are then connected to aggregation switches to form clusters. High-capacity aggregation routers (or core switches) are used to connect aggregation switches. At the top, core routers interconnect aggregation routers and interface with the Internet. This type of architecture, however, has several scalability problems. First, bandwidth is allocated on each layer and a certain oversubscription rate is used between layers. Oversubscription can contribute to congestion during data exchange among servers. Second, latency is introduced by multiple store-and-forward processes where queueing and processing delays take place at each switch/router on a data path. Third, this architecture typically involves complexity in wiring and control.
Accordingly, a need exists for methods and apparatus for a data center network with improved oversubscription rates, lower network latency, and simplified optical interconnect.